package com.itheima.reggie.filter;

import com.alibaba.fastjson.JSON;
import com.itheima.reggie.common.BaseContext;
import com.itheima.reggie.common.R;
import lombok.extern.slf4j.Slf4j;
import org.springframework.util.AntPathMatcher;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

//完善登录功能：用户不登陆也可以直接访问到系统页面

@Slf4j
@WebFilter(filterName = "loginCheckFilter",urlPatterns = "/*")
public class LoginCheckFilter implements Filter {

    //路径匹配器，支持通配符
    public static final AntPathMatcher PATH_MATCHER = new AntPathMatcher();


    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest request = (HttpServletRequest)servletRequest;
        HttpServletResponse response = (HttpServletResponse)servletResponse;

        //1、获取本次请求的url
        String requestURI = request.getRequestURI();

        //定义不需要处理的请求路径
        String[] urls = new String[]{
                "/employee/login",
                "/employee/logout",
                "/backend/**",                 // 一个 * 和两个 **的区别
                "/front/**",
                "/common/**",
                "/user/login",
                "/user/sendMsg"
        };

        //2、判断本次请求是否需要处理 处理即是否需要检查用户已经完成登录
        boolean check = check(requestURI,urls);

        //3、如果不需要处理，则直接放行
        if (check){
            filterChain.doFilter(request,response);
            return;
        }

        //4、判断登陆状态，如果已经登陆，则直接放行
        if (request.getSession().getAttribute("employee") != null){

            Long empId = (Long)request.getSession().getAttribute("employee");
            BaseContext.setCurrentId(empId);

            filterChain.doFilter(request,response);
            return;

        }

        //4-2、判断登录状态，如果已登录，则直接放行
        if(request.getSession().getAttribute("user") != null){
            log.info("用户已登录，用户id为：{}",request.getSession().getAttribute("user"));

            Long userId = (Long) request.getSession().getAttribute("user");
            BaseContext.setCurrentId(userId);

            filterChain.doFilter(request,response);
            return;
        }

        //5、如果未登录则返回未登录结果，通过输出流的方式向客户端页面响应数据
        response.getWriter().write(JSON.toJSONString(R.error("NOTLOGIN")));
        return;  // 结束方法

        //跳转页面 在前端

    }


    /**
     * 路径匹配方法，判断本次请求是否需要处理
     * @param requestURL
     * @param urls
     * @return
     */
    public boolean check (String requestURL,String[] urls){
        for (String url : urls) {
            boolean match = PATH_MATCHER.match(url, requestURL);
            if (match){
                return true;
            }
        }
        return false;
    }
}
